Projectile and missiles fuzes contain a safety and arming (S&A) device. Historically, this device has been mechanical and was driven by inertial forces reacting to acceleration of the S&A. The S&A must sense two independent "signatures" which attest to proper launch. Commonly used signatures have been setback (linear acceleration) and spin (centrifugal acceleration). Setback acceleration is realized upon firing of the projectile, while spin is realized by means of rifling twist. For projectiles which do not spin, air flow can be used as a second signature.
Use of air flow as a signature as well as a power source for a fuze is known. Devices known in the art involve the use of fluid oscillators mounted internally of the fuze. Ram air is passed into the fuze cavity to power the oscillator. The oscillator then powers a piezo-electric crystal to generate electrical signals or currents. Examples of such devices are found in U.S. Pat. Nos. 3,666,976 to Gourlay et al; 3,757,695 to Fisher; 3,781,575 to Campagnuolo; 3,787,741 to Gourlay; 3,861,313 to Campagnuolo et al; and 4,005,319 to Nilsson et al. These devices are somewhat complex in their structure and rather costly to manufacture. Further, they occupy a substantial amount of space in the interior of the fuze, where space is at a great premium.